Analysing Wind Farm Foundation Installation – Part 6: Work Faster – Two Vessels On Hire

As we’ve moved through this analysis process and applied Mermaid to the consideration of how we can baseline and improve our performance two main objectives have repeatedly arisen:

  • Work entirely in the spring and summer to reduce winter downtime.
  • Maximise the time spent performing offshore operations when favourable conditions occur by reducing the number of transits required.

Here we are going to perform two simulations which it is hope will improve our performance.

The Simulations

There are two scenarios under consideration here:

  • Two vessels operating, both vessels can carry a set of foundations at a time, one vessel is from the base case, the other is a different, slightly less capable vessel (i.e.
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Analysing Wind Farm Foundation Installation – Part 5: Reduce Transits to Improve Performance – Offshore Resupplies

In this post we’re going to look at bringing the foundations to the installation vessel at site.  It’s thought that, as with carrying more components, we can increase the working time by transiting less.  If another vessel (a barge and tugs) brings components to the main vessel the transit requirements are reduced, although it’s worth noting that offshore transfers of this type are quite strictly limited; the trade-off between transit reduction and sensitive operations is the main concern here.

The Simulation

Our base case simulation includes the transfer of installation components to the installation vessel from a storage barge in the port.  Read more >

Limiting the maximum suspension time for tasks which are allowed to suspend

Indefinite suspensions

For a long time it has been possible to allow tasks and groups of work in Mermaid to suspend, meaning that work is allowed to stop once it has started but before it is complete.  There are two cases for this, Fully Suspendable which allows the vessel to come and go as it pleases, and If Holding Station which requires the vessel(s) to remain at the working location throughout the suspension.  In both cases the length of time for which work can stop has been unlimited.   Read more >

Analysing Wind Farm Foundation Installation – Part 4: Improve Performance – Split Installation

In the last post in this series we identified that even with a larger carrying capacity, our work force was still unable to fully exploit the preferable summer weather and that all start options performed at least some work during the winter.  In this post we’re looking at splitting our installation process into two halves.

The Simulation

To see if we can gain a performance improvement by better exploiting the summer season we are going to install the foundations in two batches of 36.  Read more >

Analysing Wind Farm Foundation Installation – Part 3: First Attempts to Improve Performance – Larger Carry

Continuing the series of posts on the analysis of offshore wind turbine installation methods, this post looks at the improvements, if any, which can be gained by increasing the carrying capacity of the installation vessel.  It is thought that time spent transiting between the vessels home port and the wind farm could be better spent on performing the installation operations, particularly in the summer months when favourable weather occurs.  To do this we’re looking at increasing the on station time by allowing the vessel to carry more monopiles and transition pieces. Read more >

Analysing Wind Farm Foundation Installation – Part 2: Initial Results

We’re looking at ways in which we can install the foundations for a North Sea offshore wind farm and using Mermaid to make decisions on the vessels and the strategy which best suit our needs.  In the previous post in this series we discussed the base case for this analysis process, this being our first look at how we might perform the work.

In this post we’re going to take a look at the results of the analysis we ran last time and we’ll try to work out how, and indeed if, we can improve things. Read more >

Modelling Unexpected Breakdown

So, as we said in the first blog post of the series, we also not only have a mechanism for modelling expected breakdowns, but can use this mechanism with a systematic philosophy of failure management for modelling unexpected breakdown on short operations.

Before we get into it, let’s consider the question we want to ask. On the face of it, we might want to know the P50 of the duration of the operation, with all risk taken into account. Read more >

Modelling Expected Breakdown

In yesterday’s entry about modelling breakdown, I introduced the idea that from next week, Mermaid enables the modelling and analysis of technical breakdown. The new feature that we’re releasing is called “Occasional Tasks”.

An Occasional task or group is one that only happens for certain repeats of its parent group. So, take this very simple task diagram for a survey job to start with:

We’ve got 60 survey lines to complete, and each one takes an hour and a half. Our “Survey One Line” group is repeated 60 times to show this. Read more >

Analysing Wind Farm Foundation Installation – Part 1: Introduction to Analysis

This is the first in a series of posts looking at how we can use Mermaid to:

  • Analyse a large offshore operation;
  • Make decisions about which vessels and strategies we want to use;
  • Optimise our offshore operation.

We’re going to perform a series of simulations to help determine what vessel and strategy we should use and when we should perform the work.  This is a fictitious case so we’ll throw a few constraints and assumptions in as we go just to make it interesting. Read more >

Modelling Technical Breakdown

Almost as soon I start talking to clients about Mermaid, one of the first things I’ve always said is, “This is a weather risk analysis tool; it doesn’t take technical breakdown into account – that’s something you’ll have to model yourself.”

Having said that, risk of technical breakdown is a real and common problem for us and our clients. We’ve had projects put at serious risk due to failures in the ability of equipment to perform, requiring repair on-site, in the middle of critical tidal windows. Read more >